[llvm-commits] CVS: llvm/docs/ReleaseNotes.html
Tanya Lattner
tonic at nondot.org
Wed May 16 16:26:01 PDT 2007
Changes in directory llvm/docs:
ReleaseNotes.html updated: 1.376 -> 1.377
---
Log message:
Merged in both release announcement guts.
---
Diffs of the changes: (+242 -13)
ReleaseNotes.html | 255 +++++++++++++++++++++++++++++++++++++++++++++++++++---
1 files changed, 242 insertions(+), 13 deletions(-)
Index: llvm/docs/ReleaseNotes.html
diff -u llvm/docs/ReleaseNotes.html:1.376 llvm/docs/ReleaseNotes.html:1.377
--- llvm/docs/ReleaseNotes.html:1.376 Tue May 15 04:21:28 2007
+++ llvm/docs/ReleaseNotes.html Wed May 16 18:25:46 2007
@@ -96,8 +96,58 @@
</p>
<ul>
-<li>ding dong llvm-gcc3 is dead</li>
-<li>bytecode -> bitcode</li>
+
+<li>llvm-gcc3 is now officially unsupported. Users are required to
+ upgrade to llvm-gcc4. llvm-gcc4 includes many features over
+ llvm-gcc3, is faster, and is much easier to build.</li>
+
+<li>Integer types are now completely signless. This means that we
+ have types like i8/i16/i32 instead of ubyte/sbyte/short/ushort/int
+ etc. LLVM operations that depend on sign have been split up into
+ separate instructions (<a href="http://llvm.org/PR950">PR950</a>).</li>
+
+<li>Arbitrary bitwidth integers (e.g. i13, i36, i42, etc) are now
+ supported in the LLVM IR and optimizations. However, neither llvm-gcc nor
+ the native code generators support non-standard width integers
+ (<a href="http://llvm.org/PR1043">PR1043</a>).</li>
+
+<li>'type planes' have been removed (<a href="http://llvm.org/PR411">PR411</a>).
+ It is no longer possible to have two values with the same name in the
+ same symbol table. This simplifies LLVM internals, allowing significant
+ speedups.</li>
+
+<li>Global variables and functions in .ll files are now prefixed with
+ @ instead of % (<a href="http://llvm.org/PR645">PR645</a>).</li>
+
+<li>The LLVM 1.x "bytecode" format has been replaced with a
+ completely new binary representation, named 'bitcode'. Because we
+ plan to maintain binary compatibility between LLVM 2.x ".bc" files,
+ this is an important change to get right. Bitcode brings a number of
+ advantages to the LLVM over the old bytecode format. It is denser
+ (files are smaller), more extensible, requires less memory to read,
+ is easier to keep backwards compatible (so LLVM 2.5 will read 2.0 .bc
+ files), and has many other nice features.</li>
+
+<li>Support was added for alignment values on load and store
+ instructions (<a href="http://www.llvm.org/PR400">PR400</a>). This
+ allows the IR to express loads that are not
+ sufficiently aligned (e.g. due to pragma packed) or to capture extra
+ alignment information. </li>
+
+<li>LLVM now has a new MSIL backend. llc - march=msil will now turn LLVM
+ into MSIL (".net") bytecode. This is still fairly early development
+ with a number of limitations.</li>
+
+<li>Support has been added for 'protected visibility' in ELF.</li>
+
+<li>Thread Local Storage with the __thread keyword was implemented along
+ with added codegen support for Linux on X86 and ARM.</li>
+
+<li>ELF symbol aliases supported has been added.</li>
+
+<li>Added support for 'polymorphic intrinsics', allowing things like
+ llvm.ctpop to work on arbitrary width integers.</li>
+
</ul>
</div>
@@ -111,8 +161,30 @@
</p>
<ul>
-<li>many new supported things</li>
-<li>easier to configure on linux</li>
+<li>Precompiled Headers (PCH) support has been implemented.</li>
+
+<li>Support for external weak linkage and hidden visibility has been added.</li>
+
+<li>Packed structure types are now supported , which allows LLVM to express
+ unaligned data more naturally.</li>
+
+<li>Inline assembly support has been improved and many bugs were fixed.
+ The two large missing features are support for 80-bit floating point stack
+ registers on X86 (<a href="http://llvm.org/PR879">PR879</a>), and support for inline asm in the C backend (<a href="http://llvm.org/PR802">PR802</a>).</li>
+
+<li>Ada support, such as nested functions, has been improved.</li>
+
+<li>Tracking function parameter/result attributes is now possible.</li>
+
+<li>Its is now easier to configure llvm-gcc for linux.</li>
+
+<li>Many enhancements have been added, such as improvements to NON_LVALUE_EXPR,
+ arrays with non-zero base, structs with variable sized fields,
+ VIEW_CONVERT_EXPR, CEIL_DIV_EXPR, and many other things.</li>
+
+<li>Improved "attribute packed" support in the CFE, and handle many
+ other obscure struct layout cases correctly.</li>
+
</ul>
</div>
@@ -125,7 +197,29 @@
</p>
<ul>
-<li></li>
+<li>The pass manager has been entirely rewritten, making it significantly
+ smaller, simpler, and more extensible. Support has been added to run
+ FunctionPasses interlaced with CallGraphSCCPasses.</li>
+
+<li>The -scalarrepl pass can now promote unions containing FP values into
+ a register, it can also handle unions of vectors of the same size.</li>
+
+<li>The predicate simplifier pass has been improved, making it able to do
+ simple value range propagation and eliminate more conditionals.</li>
+
+<li>There is a new new LoopPass class. The passmanager has been
+ modified to support it, and all existing loop xforms have been
+ converted to use it. </li>
+
+<li>There is a new loop rotation pass, which converts "for loops" into
+ "do/while loops", where the condition is at the bottom of the loop.</li>
+
+<li>ModulePasses may now use the result of FunctionPasses.</li>
+
+<li>The [Post]DominatorSet classes have been removed from LLVM and clients switched to use the far-more-efficient ETForest class instead. </li>
+
+<li>The ImmediateDominator class has also been removed, and clients have been switched to use DominatorTree instead.</li>
+
</ul>
</div>
@@ -140,14 +234,64 @@
</p>
<ul>
-<li></li>
+<li>Support for Zero-cost DWARF exception handling has been added. It is mostly
+ complete and just in need of continued bug fixes and optimizations at
+ this point.</li>
+
+<li>Progress has been made on a direct Mach-o .o file writer. Many small
+ apps work, but it is not quite complete yet.</li>
+
+<li>Support was added for software floating point routines.</li>
+
+<li>DWARF debug information generation has been improved. LLVM now passes
+ most of the GDB testsuite on MacOS and debug info is more dense.</li>
+
+<li>A new register scavenger has been implemented, which is useful for
+ finding free registers after register allocation. This is useful when
+ rewriting frame references on RISC targets, for example.</li>
+
+<li>Heuristics have been added to avoid coalescing vregs with very large live
+ ranges to physregs.</li>
+
+<li>Support now exists for very simple (but still very useful)
+ rematerialization the register allocator, enough to move
+ instructions like "load immediate" and constant pool loads.</li>
+
+<li>Significantly improved 'switch' lowering, improving codegen for
+ sparse switches that have dense subregions, and implemented support
+ for the shift/and trick.</li>
+
+<li>The code generator now has more accurate and general hooks for
+ describing addressing modes ("isLegalAddressingMode") to
+ optimizations like loop strength reduction and code sinking.</li>
+
+<li>The Loop Strength Reduction pass has been improved, and support added
+ for sinking expressions across blocks to reduce register pressure.</li>
+
+<li>Added support for tracking physreg sub-registers and super-registers
+ in the code generator, as well as extensive register
+ allocator changes to track them.</li>
+
+<li>There is initial support for virtreg sub-registers
+ (<a href="http://llvm.org/PR1350">PR1350</a>).</li>
+
</ul>
<p>In addition, the LLVM target description format has itself been extended in
several ways:</p>
<ul>
-<li></li>
+<li>Extended TargetData to support better target parameterization in
+ the .ll/.bc files, eliminating the 'pointersize/endianness' attributes
+ in the files (<a href="http://llvm.org/PR761">PR761</a>).</li>
+
+<li>TargetData was generalized for finer grained alignment handling,
+ handling of vector alignment, and handling of preferred alignment</li>
+
+<li>LLVM now supports describing target calling conventions
+ explicitly in .td files, reducing the amount of C++ code that needs
+ to be written for a port.</li>
+
</ul>
<p>Further, several significant target-specific enhancements are included in
@@ -165,25 +309,110 @@
<div class="doc_text">
-<p>New features include:
+<p>X86-Specific Code Generator Enhancements:
</p>
<ul>
-<li></li>
+<li>The scheduler was improved to better reduce register pressure on
+ X86 and other targets that are register pressure sensitive</li>
+<li>Linux/x86-64 support has been improved.</li>
+<li>PIC support for linux/x86 has been added.</li>
+<li>Support now exists for the GCC regparm attribute, and code in the X86
+ backend to respect it.</li>
+<li>Various improvements have been made for the X86-64 JIT, allowing it to
+ generate code in the large code model</li>
+<li>LLVM now supports inline asm with multiple constraint letters per operand
+ (like "ri") which is common in X86 inline asms.</li>
+<li>Early support has been added for X86 inline asm in the C backend.</li>
+<li>Added support for the X86 MMX instruction set.</li>
+
</ul>
-
+
+<p>ARM-Specific Code Generator Enhancements:
+</p>
+
+<ul>
+<li>Several improvements have been made to the ARM backend, including basic
+ inline asm support, weak linkage support, static ctor/dtor support and
+ many bug fixes.</li>
+<li>There are major enhancements to the ARM backend, including support for ARM
+ v4-v6, vfp support, soft float, pre/postinc support, load/store multiple
+ generation, constant pool entry motion (to support large functions),
+ and enhancements to ARM constant island pass.
+ </li>
+<li>Added support for Thumb code generation (an ARM subtarget).</li>
+<li>More aggressive size analysis for ARM inline asm strings was
+ implemented.</li>
+</ul>
+
+</div>
+
+<p>Other Target-Specific Code Generator Enhancements:
+</p>
+
+<ul>
+<li>The PowerPC 64 JIT now supports addressing code loaded above the 2G
+ boundary.</li>
+
+<li>Improved support for the Linux/ppc ABI and the linux/ppc JIT is fully
+ functional now. llvm-gcc and static compilation are not fully supported
+ yet though.<</li>
+
+<li>Many bugs fixed for PowerPC 64.</li>
+
+<li>Support was added for the ARM AAPCS and EABI ABIs and PIC codegen on
+ arm/linux.</li>
+
+<li>Several bugs in DWARF debug emission on linux and cygwin/mingw were fixed.
+ Debugging basically works on these targets now.</li>
+
+<li>Support has been added for the X86-64 large code model to the JIT,
+ which is useful if JIT'd function bodies are more than 2G away from
+ library functions.</li>
+
+<li>Several bugs were fixed for DWARF debug info generation on arm/linux.</li>
+
+</ul>
+
</div>
<!--_________________________________________________________________________-->
<div class="doc_subsubsection"><a name="other">Other Improvements</a></div>
<div class="doc_text">
-<p></p>
+
+<p>This release includes many other improvements, including
+performance work, specifically designed to tune datastructure
+usage. This makes several critical components faster.</p>
<p>More specific changes include:</p>
<ul>
-<li></li>
+<li>ConstantBool, ConstantIntegral and ConstantInt classes have been merged
+ together, we now just have ConstantInt</li>
+
+<li>LLVM no longer relies on static destructors to shut itself down. Instead,
+ it lazily initializes itself and shuts down when llvm_shutdown() is
+ explicitly called.</li>
+
+<li>LLVM now has significantly fewer static constructors, reducing startup time.
+ </li>
+
+<li>Several classes have been refactored to reduce the amount of code that
+ gets linked into apps that use the JIT.</li>
+
+<li>Construction of intrinsic function declarations has been simplified.</li>
+
+<li>The llvm-upgrade tool now exists. This migrates LLVM 1.9 .ll files to
+ LLVM 2.0 syntax.</li>
+
+<li>The gccas/gccld tools have been removed.</li>
+
+<li>Support has been added to llvm-test for running on low-memory
+ or slow machines (make SMALL_PROBLEM_SIZE=1).</li>
+
+<li>llvm-test is now more portable and should build with MS Visual Studio.</li>
+
</ul>
</div>
@@ -610,7 +839,7 @@
src="http://www.w3.org/Icons/valid-html401" alt="Valid HTML 4.01!" /></a>
<a href="http://llvm.org/">The LLVM Compiler Infrastructure</a><br>
- Last modified: $Date: 2007/05/15 09:21:28 $
+ Last modified: $Date: 2007/05/16 23:25:46 $
</address>
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